A new synchronous motor is a high-efficiency AC machine that has a low starting current. It may be used for conventional loads and also to start high inertia loads, delivering a constant torque during starting. Acceleration to synchronous speed can be allowed to take several minutes, if necessary, because the low starting current precludes excessive heating in the motor. Some of these motors are constructed with integral high inertia rotors that act as flywheels. These synchronous motors can "ride through" power sags and interruptions up to 30 seconds or more while still delivering useful load to pumps, fans, blowers, and compressors. The motors also restart instantly and resynchronize when utility power recovers. The motor can be useful in many heating, ventilating, and air-conditioning (HVAC) applications including those where machines and processes might otherwise be forced to shut down during momentary power interruptions.

Units: I-P